The invention relates to balances or scales, with an enclosed weighing area which surrounds this balance scale on all sides and which can be opened and closed along at least part of one side by shifting a moveable wall element and with control electronics for the moveable wall element and with control electronics for the drive motor.
Balances with wind guards are known. For example, DE-OS 37 41 313 describes such a balance which comprises a cylindrical wind guard, and EP 0 234 008 describes a balance with a boxlike wind guard.
A disadvantage of these known balances is the fact that the time required for a complete opening and closing of the weighing area by the motor is relatively long and additional time must pass before air turbulence in the weighing area has completely subsided after the closing of the wind guard.
Other balances or scales with wind guards with at least two moveable wall elements, which can be opened or closed either by hand or by a motor, with a display unit, an electronic control, and an opening control buttons, whereby at least two of the opening keys are assigned to the motor-operation of the wind guard.
A balance of this type is known from U.S. Pat. No. 5,058,692 to Melcher et. al. In U.S. Pat. No. 5,058,692 a learning phase is described, which is activated by the operation of a key or a combination of keys and by which the desired end position of the wind guard at opening will be stored.
A disadvantage of this known balance is the fact that the assignment of the moveable wall elements to the operating keys is not very flexible and that the activation of the learning phase requires an additional key or the remembering of a specific combination of keys.
The invention has the object of designing a balance with a motor driven wind guard in such a manner that the opening and closing of the weighing area is faster and there is diminished subsequent air turbulence.